Field of the Invention
The present invention relates to a surgery assistance apparatus, method and program that presents an excision region including an abnormal region of an organ, such as a liver and a lung or lungs, in surgery of the organ.
Description of the Related Art
When surgery is performed to excise an abnormal region in an organ, such as a liver and a lung or lungs, a three-dimensional medical image representing the morphology of a target organ is obtained before surgery, for example, by performing CT (Computed Tomography) examination or MRI (Magnetic Resonance Imaging) examination. An excision region is determined in advance based on the three-dimensional medical image.
As a method for determining the excision region based on the three-dimensional medical image, for example, the following method has been proposed. Blood vessels and a bronchus or bronchi are extracted from the three-dimensional medical image, and a region of an organ to which oxygen and nutrition are supplied by a part of these regions that is related to an abnormal region is extracted, as a dominated region. This dominated region is determined, as the excision region.
Meanwhile, a surgical procedure of partial excision has been proposed for surgery of an abnormal region located near the surface of a target organ. The partial excision is performed in such a manner to scoop out a region so as not to damage the blood vessels and the bronchus or bronchi (for example, please refer to M. Makuuchi et al., “Surgery for Small Liver Cancers”, Seminars in Surgical Oncology, Vol. 9, Issue 4, pp. 298-304, 1993). Further, Japanese Patent No. 4193201 proposes the following method, as a method for determining an excision region. A region is expanded, based on a diseased region in the liver and plural vessels running through the liver, outward in spherical shape from the center or the center of gravity of the diseased region until the expanded region touches one of the plural vessels. Further, a substantially circular cone region that touches the expanded spherical region is determined as the excision region.